Preheat oven to 350°F (180°C). Mix peanuts, sugar, butter and 1/2 teaspoon (2ml) of the cinnamon in medium bowl. Remove 1/4 cup (60ml) and spread on small baking sheet. Divide remaining peanut mixture among 4 (4-inch/10cm) tart pans with removable bottoms. Press firmly onto bottom and up sides of each tart pan.